tec:
I mean... ignore 'do not murder'... and you have screwed up your life AND many others' lives, all in one go.
'God' isn't the source of laws about not murdering people. Quite early on in human society, it was recognised that mutual trust is beneficial in human social groups, and going around murdering people disrupts that trust. Of course that doesn't mean no one will ever murder anyone, because an individual's own motivations sometimes outweigh the social construct. It's nothing to do with 'God'.
The 'God' of the Bible is purportedly responsible for instructing people to murder though.